The present invention relates to Nxcex5-long chain acyllysine crystals. When the Nxcex5-long chain acyllysine crystals were used in cosmetics, there is provided cosmetics which have a good feeling during use such as spreadability, etc., no gleam caused by irregular light reflection, and which reduce the xe2x80x9cstickinessxe2x80x9d based on the oily raw materials incorporated therein and which are excellent in sustaining the makeup effect.
Nxcex5-Long chain acyllysine has a good lubricity owing to its peculiar plate crystal structure so that it is being used in cosmetics for the purpose of adjusting the feeling, etc. during use. The Nxcex5-long chain acyllysine may be prepared, for example by a process which comprises heating a higher fatty acid salt of lysine at 100xcx9c250xc2x0 C. to cause dehydration (Japanese Patent Application Laid-Open No. 1513/1974). Also, it is known to be prepared by a process which comprises adding crude crystals of Nxcex5-long chain acyllysine to an aqueous medium below pH 2 or above pH 11, dissolving Nxcex5-long chain acyllysine in the aqueous medium by heating the mixture to 40xcx9c60xc2x0 C. while stirring, and thereafter neutralizing the resultant solution to pH 6.5 by adding slowly dropwise a basic medium or an acidic medium while being kept to this temperature thereby Nxcex5-long chain acyllysine is crystallized out.(Japanese Patent Application Laid-Open No. 242563/1989). However, an average particle diameter or a mode diameter of the Nxcex5-long chain acyllysine crystals obtained by these known processes is as large as 15 xcexcm or more so that when they were incorporated into cosmetics there occurs an irregular light reflection due to their plate structure to cause the so-called xe2x80x9cgleamxe2x80x9d. And, in the case of cosmetics where this xe2x80x9cgleamxe2x80x9d is not preferable, there was a problem that the amount added of the Nxcex5-long chain acyllysine is restricted to some extent.
In this connection, oily raw materials such as an oil and fat, a wax, a hydrocarbon, a fatty acid, a higher alcohol, esters and the like are being used in cosmetics for enhancing emollient effect including controlling transpiration of water from the skin. However, when such oily raw materials were incorporated in a large amount for enhancing emollient effect, the xe2x80x9cstickinessxe2x80x9d is increased so that the feeling during use is not preferable.
In order to reducing the xe2x80x9cstickinessxe2x80x9d of the oily raw materials, Nxcex5-long chain acyllysine crystals are known to be incorporated in cosmetics (Japanese Patent Application Laid-Open No. 74312/ 1991).
Since the average particle diameter or the mode diameter of the Nxcex5-long chain acyllysine crystals is as large as 15 xcexcm or more as stated above, their reducing effect on the xe2x80x9cstickinessxe2x80x9d is small and for this reason their use was not necessarily satisfactory.
On the other hand, as a means of making the particle size of the Nxcex5-long chain acyllysine small, a dry or wet pulverization process is known to be applied to it (Japanese Patent Application Laid-Open No. 323914/1997). Although the pulverized Nxcex5-long chain acyllysine powder which may be obtained by these pulverization processes has not only a little xe2x80x9cgleamxe2x80x9d caused by the plate structure and but also effect to reduce the xe2x80x9cstickinessxe2x80x9d based on the oily raw materials, the crystal form is broken owing to the mechanical pulverization to cause the problems that the cosmetics containing it have a bad spreadability and unpleasant feeling when applied to the skin or the hair and that many steps are necessary for its preparation.
Also, as another means to make the particle size small, it is reported that a basic solution of Nxcex5-long chain acyllysine is added dropwise to an acidic solution such as hydrochloric acid thereby obtaining fine crystals of 0.01xcx9c3 xcexcm in the terms of the projected diameter when observed under an electron microscope (Japanese Patent Application Laid-Open No. 337519/ 1996). However, when the crystals obtained by this process were measured with a particle size distribution meter, their average particle diameter or their mode diameter lies in the vicinity of 18 xcexcm which does not coincide with the value of the projected diameter observed under the electron microscope, thus they have still large particle size. And therefore, the xe2x80x9cgleamxe2x80x9d caused by the irregular light reflection due to their plate structure was increased and further the xe2x80x9cstickinessxe2x80x9d due to the oily raw materials could not be reduced sufficiently and the feeling during use was not satisfactory.
An object of the invention is to provide cosmetics which do not cause any irregular light reflection, i.e. the xe2x80x9cgleamxe2x80x9d even when applied to the skin and the hair, giving a good feeling during use such as spreadability, etc., and which is excellent in the sustaining of the makeup effect.
Another object of the invention is to provide cosmetics containing an oily raw material, said cosmetics having a high emollient effect and no xe2x80x9cstickinessxe2x80x9d and being excellent in lubricity during use.
As a result of having ardently studied considering such actual situation, the present inventors have found that by using Nxcex5-long chain acyllysine crystals whose average particle diameter or mode diameter is set to the range of 3xcx9c15 xcexcm without being mechanically pulverized there can be provided cosmetics which do not have gleam and stickiness when applied to the skin and the hair, giving a good feeling during use such as spreadability, etc., and being excellent in sustaining the makeup effect. And the present invention has been completed based on the above finding.
That is, the present invention is characterized by being non-pulverized Nxcex5-long chain acyllysine crystals whose average particle diameter and/or mode diameter is 3xcx9c15 xcexcm.
Also, the present invention is characterized by being Nxcex5-long chain acyllysine crystals obtained by dissolving Nxcex5-long chain acyllysine in an acidic solvent or a basic solvent consisting of one or more selected from lower alcohols and/or water and thereafter neutralizing the resultant solution by adding dropwise a basic solution or an acidic solution at a temperature below 35xc2x0 C. to crystallize out Nxcex5-long chain acyllysine.
Also, the present invention relates to powders treated wherein powders for cosmetic use have been subjected to dry surface treatment with one or more selected from said crystals.
Further, the present invention is cosmetics which are characterized by containing said crystals or said powders treated.
Furthermore, the present invention is cosmetics which are characterized by containing an oily raw material in combination with said crystals.
Also, the present invention relates to a process for preparing Nxcex5-long chain acyllysine crystals which is characterized by dissolving Nxcex5-long chain acyllysine in an acidic solvent or a basic solvent consisting of one or more selected from lower alcohols and/or water and thereafter neutralizing the resultant solution by adding dropwise a basic solution or an acidic solution at a temperature below 35xc2x0 C. to crystallize out Nxcex5-long chain acyllysine.
Firstly, Nxcex5-long chain acyllysine crystals of the present invention and a process for preparing the same are illustrated.
The raw material Nxcex5-long chain acyllysine which may be employed in a process for preparing crystals of the present invention may be synthesized by the known process described in Japanese Patent Application Laid-Open No. 1513/1974. Also, a commercially available product (for example, xe2x80x9cAmihopexe2x80x9d, a trade name, a product of Ajinomoto Co., Inc.) may be employed.
The long chain acyl groups in the Nxcex5-long chain acyllysine are those of saturated or unsaturated fatty acids having 8xcx9c22 carbon atoms. If they are exemplified, oleyl, lauroyl, myristyl, stearyl, palmityl, octyldodecyl, behenyl, acyl of coconut oil fatty acid, acyl of palm kernel oil fatty acid, acyl of tallow oil fatty acid and so on are taken, but lauroyl group is preferred from the standpoint of view of being widely available.
Also, Nxcex5-long chain acyllysine for use in the present invention may be represented by the following general formula (1) 
(wherein R represents a straight or branched chain alkyl or alkenyl group having 7xcx9c21 carbon atoms)
As examples of a lower alcohol which may be employed for the crystallization, aliphatic alcohols having 1xcx9c4 carbon atoms such as methanol, ethanol, propanol, butanol, isopropanol and the like are taken. However, methanol, ethanol, isopropanol are preferred. These lower alcohols may be used singly or in admixture with two or more of kinds.
The ratio of lower alcohol to water is not limited particularly and it may be in the range of lower alcohol/water=0/100xcx9c100/0, preferably 55/45xcx9c70/30 in terms of weight ratio. That is, in the case that the weight ratio of the both is smaller than 55/45 or otherwise in the case that it is larger than 70/30, the solubility of the Nxcex5-long chain acyllysine is decreased so that a large amount of the solvent is needed for dissolving it and the efficiency is lowered.
Next, to the above solvent is added an acid or a base to make an acidic or basic solvent which dissolves the Nxcex5-long chain acyllysine.
As an acid to be used, it may be either an organic acid or an inorganic acid. If it is exemplified, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, citric acid, lactic acid, glutamic acid, pyrrolidonecarboxylic acid and the like are taken, but sulfuric acid and hydrochloric acid are preferred.
As a base to be used, it may be either an organic base or an inorganic base. For example, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, sodium carbonate, ammonia, triethylamine, triethanolamine, monoethanolamine, pyridine and the like are taken, but sodium hydroxide and potassium hydroxide are preferred.
The amount of the acid or the base to be added in this case is not limited particularly and it may be any one if it is sufficient to dissolve Nxcex5-long chain acyllysine.
Next, the acidic solvent or the basic solvent in which N-long chain acyllysine has been dissolved is kept to a temperature below 35xc2x0 C. and neutralized by adding dropwise a basic solution or an acidic solution to crystallize out N-long chain acyllysine.
The temperature at which the crystallization is conducted is not limited particularly so long as it is below 35xc2x0 C. However, the temperature below 28xc2x0 C. is particularly preferable from the standpoint of view that the crystals having a small average particle diameter and/or mode diameter may be obtained. Also, the lower limitation of the crystallization temperature may be below the coagulation point of the solvent used.
When the crystallization temperature exceeds 35xc2x0 C., the obtained Nxcex5-long chain acyllysine crystals have such a large average particle diameter and mode diameter as 15 xcexcm or more and become thick and plate crystal so that when they were incorporated into cosmetics, not only the gleam is recognized due to their plate structure but also the xe2x80x9cstickinessxe2x80x9d based on the oily raw material can not be reduced sufficiently because of their large size diameter, thus being not preferable.
The basic or acidic solution for use in the crystallization may be prepared with the acid or the base as stated above.
The process to isolate and dry the formed crystals may be conducted according to the conventional manner.
The crystals obtained according to the present invention have an average diameter and a mode diameter of 3xcx9c15 xcexcm when measured with a particle size distribution meter of LS230 type manufactured by Coulter Inc.
The measurement of the average diameter and the mode diameter is conducted by using isopropanol as a dispersing solvent, adjusting the concentration of the compound to be tested in said dispersing solvent so as to become about 16% and controlling the circulation speed so as to be 10 L/min.
The average diameter and the mode diameter defined herein are ones determined using a volume cumulative value. Also, the mode diameter means the particle size which becomes the maximum frequency.
The followings illustrate the powders treated which is characterized by having subjected powders for cosmetic use to dry surface treatment with one or more selected from said crystals.
The powders for cosmetic use which may be used in the present invention are not particularly limited if they are ones (pigments, coloring materials, resins) used in cosmetics. Examples of such powders include resin powders such as nylon beads, silicone beads and the like; nylon powder, metallic fatty acid soap, yellow iron oxide, red iron oxide, black iron oxide, chromium oxide, cobalt oxide, carbon black, Ultramarine, iron blue, zinc oxide, titanium oxide, zirconium oxide, silicon dioxide, aluminum oxide, cerium oxide, mica titanium, boron nitride, barium sulfate, calcium carbonate, magnesium carbonate, aluminum silicate, magnesium silicate, silicon carbide, pigment, lake, sericite, mica, talc, kaolin, plate barium sulfate, butterfly barium sulfate, fine particle titanium oxide, fine particle zinc oxide, fine particle iron oxide and the like. Furthermore, they may be ones wherein there has been applied a surface-treatment such as silicon-treatment, fluorine compound-treatment, silane coupling agent-treatment, silane treated organic titanate-treatment, fatty acid-treatment, metallic soap-treatment, oil agent-treatment, amino acid-treatment or the like. The process for surface-treatment may be conducted by a dry treatment usually used.
Next, cosmetics which are characterized by containing said N-long chain acyllysine crystals or said powders treated are illustrated.
Although the amount of said crystals or said powders treated to be incorporated into cosmetics may be greatly varied depending on the form of cosmetics, it is 0.1xcx9c99% by weight in makeup and basic cosmetics while it is 0.1xcx9c30% by weight in hair and cleaning cosmetics.
Next, an oily raw material for use in the present invention is not limited particularly and there may be used oils which have been widely used as the raw material for cosmetics.
Examples of an oil include higher alcohols such as cetyl alcohol, isostearyl alcohol, lauryl alcohol, hexadexyl alcohol, octyl dodecanol and the like; fatty acids such as isostearic acid. undecylic acid,_oleic acid and the like; polydric alcohols such as glycerin, sorbitol, ethylene glycol, propylene glycol, polyethlene glycol and the like; esters such as myristyl myristate, hexyl laurate, decyl oleate, isopropyl myristate, hexyldecyl dimethyloctanoate, glycerol monostearate, diethyl phthalate, ethylene glycol monostearate, octyl hydroxystearate and the like; hydrocarbons such as liquid paraffin, vaseline, squalane and the like; waxes such as lanolin, hydrogenated lanolin, carnauba wax and the like; fat and oils such as mink oil, cacao oil, coconut oil, palm kernel oil, camellia oil, sesame oil, castor oil, olive oil and the like; ethylene-xcex1-olefin co-oligomer and the like.
Also, examples of another form of oils include silicone compounds such as dimethyl polysiloxane, methyl hydrogen polysiloxane, methyl phenyl polysiloxane, polyether-modified organopolysiloxane, fluoroalkyl polyoxyalkylene co-modified organopolysiloxane, alkyl-modified organopolysiloxane, terminal-modified organopolysiloxane, fluoro-modified organopolysiloxane, aminodimethicone, amino-modified organopolysiloxane, silicone gel, acryl silicone, trimethylsiloxy silicic acid, silicone RTV rubber and the like; fluorine compounds such as perfluorocarbon, fluoroalcohol and the like.
In addition to the above components, there may be incorporated into the cosmetics of the present invention at the same time components usually used in cosmetics inclusive a fluorine compound, a resin, a surfactant, a thickener, a high molecular compound, an antiseptic, a perfume, an ultraviolet absorber (includes an organic and an inorganic ones, and may be one susceptible to either UV-A or UV-B), a humectant, a hystologically active substance, salts, a solvent, an antioxidant, an antibacterial agent, an anhidrotics, a chelating agent, a neutralizer, a pH adjusting agent and the like.
As a surfactant, for example an anionic surfactant, a cationic surfactant, a nonionic surfactant and betaine type surfactant may be used.
Examples of an organic ultraviolet absorber include 2-ethylhexyl p-methoxy cinnamate, 2-ethylhexyl p-dimethyl-aminobenzoate, 2-hydroxy-4-methoxybenzophenone-5- sulfuric acid, 2,2xe2x80x2-dihydroxy-4-methoxybenzophenone, diethanolamine salt of p-methoxyhydrocinnamic acid, p-aminobenzoic acid (hereinafter, referred to as PABA), ethyl dihydroxy propyl PABA, gryceryl PABA, homomethyl salicylate, methyl-o-aminobenzoate, 2 - ethylhexyl- 2 - cyano- 3,3 - diphenylacrylate, octyl dim ethyl PABA, octyl methoxycinnamate, 2-phenyl-benzimidazole-5-sulfuric acid, triethanolamine salt of salicylic acid, 3-(4-methylbenzylidene) camphor, 2,4-dihydroxybenzophenone, 2,2xe2x80x2, 4,4xe2x80x2-tetrahydroxy-benzophenone, 2,2xe2x80x2-dihydroxy-4,4xe2x80x2-dimethoxybenzophenone, 2-hydroxy-4-N-octoxybenzophenone, 4-isopropyl dibenzoylmethane, butyl methoxy dibenzoylmethane, 2-ethylhexyl 4-(3, 4-dimethoxyphenymethylene) -2, 5-dioxo- 1-imidazolidine propionate and the like.
Examples of the solvent include cyclic silicone, ethanol, soft liquid isoparaffin, lower alcohol, ethers, LPG, fluorocarbon, N-methylpyrrolidone, fluoroalcohol, volatile straight chain silicone and the like.
The cosmetics of the present invention may be any form inclusive powders, liquid, cream, paste, cake and solid. Specifically, makeup cosmetics such as a foundation, a face powder, a cheek rouge, an eye shadow and the like; body cosmetics such as a body powder, a baby powder and the like;
basic cosmetics such as a lotion, a milky lotion, a facial liquid essence, a skin cream, a sun care product and the like; cleaning agents such as a cleansing powder, a hair shampoo, a body shampoo, a hand soap, a solid soap and the like; hair cosmetics such as a rinse, a treatment, a styling agent, an anhidrotics, a bathing agent, a hair dye and the like.
The cosmetics of the present invention may be prepared according to the conventional process.
Best Modes For Carrying Out the Invention